High temperature fan construction

ABSTRACT

A high temperature fan hub is secured to a hollow drive shaft by hollow driving pins projecting radially above the hub and extending transversely of the hub and shaft to communicate with the bore of the shaft. The hub has an end wall enclosing the bore at that end of the shaft to which it is secured and rotation of the shaft causes cooling fluid to be pumped from a remote point of the shaft such as the end of the shaft through the shaft bore and driving pins by centrifugal force to cool the hub and shaft at the joint thereof.

United States Patent Mercer 14 1 Aug. 1, 1972 [54] HIGH TEMPERATURE FAN 3,149,819 9/1964 Baumann et a1. ..308/77 CONSTRUCTION 3,370,830 2/1968 Nickles et a1. ..4l6/95 [72] Inventor: Robert Mercer, Cohasset, Mass. FORElGN PATENTS OR APPLICATIONS Assigneer Westinghouse Electric Corporation, 62,010 12/1954 France ..415/180 P1ttsbur8h,Pa- 975,892 11/1964 Great Britain ..415/180 [22] Filed: March 1971 Primary Examiner-Henry F. Raduazo [21] Appl. No.: 122,563 At10rneyF. H. Henson and F. E. Blake 52 US. Cl. ..415/180, 308/77, 287/5208 [57] ABSTRACT [51] Int. Cl ..F04d 29/58, Fl6n 1/00, F 16d l/O6 A high temperature fan hub is secured to a hollow [58] Field of Search ...415/1l5, 106, 104, 107; drive h f by hollow driving pins projecting radially 303 77; 237 520 53 41 95 above the hub and extending transversely of the hub and shaft to communicate with the bore of the shaft. [56] References Cited The hub has an end wall enclosing the bore at that end of the shaft to which it is secured and rotation of the UNITED STATES PATENTS shaft causes cooling fluid to be pumped from a remote point of the shaft such as the end of the shaft through the shaft bore and driving pins by centrifugal force to 1th hb dhft'tth "tth f. 2,651,496 9/1953 Bucklanol et a]. ..415/180 C u s a 2,733,106 1/ 1956 Kulling ..308/77 5 Claims, 3 Drawing Figures I l 1, l

I ll 22 I l6 l5 l2 :1 E: 1 l 30 Jl l \\23 PATENTEDMJB 1 m2 WITNESSES 4-6.&,/); .M/

INVENTOR Robert Mercer ATTORNEY HIGH TEMPERATURE FAN CONSTRUCTION CROSS REFERENCE TO RELATED PATENT APPLICATIONS So far as is known this invention is not related to any pending patent applications.

BACKGROUND OF THE INVENTION Fans intended for use where the fan rotor may be subjected to a very high temperature must be carefully designed to protect the bearings from damage and to prevent undesired distortions of the fan parts due to the excessive heat encountered during operation of the fan. Many arrangements for cooling bearing and shaft structures are known for application to high temperature fan constructions, but they are relatively complex and difficult to use. There is considerable demand for a simple arrangement for cooling a fan hub and the associated shaft in the manner to enable various conventional forms of bearings, such as roller or ball bearings to be used withoutdamage by the heat from the fan rotor during fan operation.

PRIOR ART:

Reference may be made to the US. Pat. No. 2,215,945 to Vincent issued Sept. 24, 1946, and to US. Pat. No. 2,601,030 to Klein et al., issued June 17, 1952, showing typical cooling arrangements for high temperature fans but not showing the unique combined fan hub shaft joint and cooling wheel of this invention.

SUMMARY OF THE INVENTION According to the invention, a high temperature fan hub is secured to one end of a hollow drive shaft with the hub having an end wall to close the bore at that end of the shaft in the assembled relation. The hub is fastened to the shaft by one or more hollow driving pins that project radially above and extend transversely through the hub and shaft in communication with the shaft bore. Thus, the driving pin functions both as a key for the hub and shaft and as a centrifugal pump to pump cooling fluid from the remote. end of the shaft through the shaft and hub as the shaft is rotated. The flow of cooling fluid thus induced serves to cool the hub and shaft joint and to prevent the flow of heat from the fan rotor to the shaft bearings which therefore may be of any suitable well-known simple design and not necessarily a high temperature design.

In one form of the invention, the fan rotor is enclosed in a suitable fan housing and the hub extends through the housing with the cooling and driving pins extending above the hub outside of the fan housing so that the cooling fluid pumped through the hollow fan drive shaft is not discharged into the fan enclosure.

Various other features and advantages of the invention will be apparent with reference to the following detailed specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a high temperature fan having the cooling arrangement of the invention;

FIG. 2 is an enlarged fragmentary sectional view through the fan hub and shaft of the invention in the form where the fan hub overlies the end of the fan drive shaft; and

FIG. 3 is a view similar to FIG. 2 but showing the form of the invention in which the fan hub is received within the end of the overlying fan drive shaft.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referringto'FIGS. l and 2 of the drawing, a first embodiment of the invention will be described. The fan rotor 10 is secured to the fan hub 11 in any suitable manner such as by welding shown at 10a. The fan hub 11 is bored to receive the end of the hollow fan drive shaft 12 with the hub 11 therefor overlying the end of the hollow fan drive shaft 12. The fan drive shaft 12 is suitably journalled in any form of bearings such as shown at 13 and 14 which may be ball or roller bearings or of other known bearing constructions not disclosed in detail. As previously mentioned, thefan drive shaft 12 is bored to provide the axial opening 15 through which cooling fluid may be passed from the remote end 30 of the fan drive shaft 12 to the vicinity of the fan hub 11. The fan hub 11 is provided with a transverse end wall 16 which functions to close that end of the hollow drive shaft 12 to which the hub 11 is secured.

In accordance with the invention, the fan hub 11 is fastened to the hollow drive shaft 12 to be rotatable therewith by one or more hollow driving pins or keys such as shown at Hand 23. Each of the hollow driving pins or keys 22 and 23 is secured to the hub 11 by any suitable means such as welds 22a and 23a respectively although the driving pins or keys 22 and 23 may be secured to the hub and shaft in any other manner known to those skilled in the art. It will be noted that each of the hollow driving pins 22 and 23 projects radially above the hub 11 so that when the fan shaft 12 together with the fan hub 11 is rotated, the respective hollow driving pin 22, 23 functions as an element of a centrifugal pump or cooling wheel to pump cooling fluid from the remote end 30 through the hollow bore 15 of the drive shaft 12 and out through the hollow driving pins 22, 23.

As shown by FIGS. 1 and 2 of the drawing, the remote end 30 of the hollow drive shaft 12 is open to the atmosphere so that when the drive shaft 12 and fan rotor 10 are rotated the simultaneous rotation of the hollow driving pins 22 and 23 will cause atmospheric air to be pumped as a cooling fluid through the drive shaft 12 and out through the hollow driving pins 22 and 23 thereby cooling the hub 11, the hot end of the hollow shaft 12 and the joint between the hub 11 and the shaft 12 and preventing excessive transmission of heat from the hot fan rotor 10 to the drive shaft 12 and its bearings 13 and 14. It should be understood however that a particular cooling, fluid other than air may be used and in that case suitable arrangements including slip collars or the like for connecting the cooling fluid to the hollow drive shaft 12 would be employed. These arrangements have not been shown in detail since they are known to those skilled in the art and do not form a significant part of the present invention.

Referring to FIG. 3 of the drawing, a second form of the invention is shown wherein the fan hub 11 is received within the bore 15 of the hollow drive shaft 12 with the drive shaft thus overlying the end of the fan hub 11.

Either form of the invention as shown by FIGS. 1-3 of the drawing may have an enclosure of the fan rotor within a fan housing 40. in such case, the fan hub 1 1 may project through a central opening 41 of the fan housing 40 and a suitable seal plate 42 may be provided about the housing opening 41 and the hub 1 l as shown. It will be noted that in the preferred forms of the invention being described, the hollow driving pins 22 and 23 project above the hub 11 at a point outside of the fan enclosure 40 and seal 42, so that the cooling fluid will be discharged outside of the fan enclosure. It should be understood however that under certain conditions of fan operation, it may be desirable to have the cooling and driving pins 22 and 23 positioned within the fan enclosure 40 so that the cooling fluid will be discharged into such enclosure and therefore this invention is not to be limited only to the arrangement wherein the hollow driving pins 22 and 23 are positioned to discharge the cooling fluid outside of the fan enclosure 40. Also it should be understood that the bore of the hollow drive shaft 12 may be provided with interior heat exchange fins configured in any suitable manner as will be well known to those skilled in the art.

Various other modifications will occur to those skilled in the art.

I claim as my invention:

l. A fan for high temperature usage comprising, a hollowdrive shaft, at least one shaft support bearing, a fan hub mounted on one end of said shaft and having a wall enclosing the one end of the shaft, and at least one hollow driving pin projecting radially above and extending through said hub and shaft in communication with the bore of said shaft, whereby cooling fluid is pumped through said shaft and pin as said shaft is rotated to thus cool the joint of said hub and shaft.

2. The invention of claim 1 in which said hub overlies said shaft.

3. The invention of claim 1 in which said shaft overlies said hub.

4. The invention of claim 1 in which a fan rotor is secured to said hub, and said hub and shaft are joined at a point between said fan rotor and the adjacent shaft bearing to thus reduce the transfer of heat from the fan rotor to said bearing.

5. The invention of claim 4 in which a fan enclosure is positioned to surround said rotor, and portions of said hub and each of said driving pins are positioned outside of said enclosure to discharge cooling fluid outside of the enclosure. 

1. A fan for high temperature usage comprising, a hollow drive shaft, at least one shaft support bearing, a fan hub mounted on one end of said shaft and having a wall enclosing the one end of the shaft, and at least one hollow driving pin projecting radially above and extending through said hub and shaft in communication with the bore of said shaft, whereby cooling fluid is pumped through said shaft and pin as said shaft is rotated to thus cool the joint of said hub and shaft.
 2. The invention of claim 1 in which said hub overlies said shaft.
 3. The invention of claim 1 in which said shaft overlies said hub.
 4. The invention of claim 1 in which a fan rotor is secured to said hub, and said hub and shaft are joined at a point between said fan rotor and the adjacent shaft bearing to thus reduce the transfer of heat from the fan rotor to said bearing.
 5. The invention of claim 4 in which a fan enclosure is positioned to surround said rotor, and portions of said hub and each of said driving pins are positioned outside of said enclosure to discharge cooling fluid outside of the enclosure. 